Electric furnace and method of melting metals and smelting ores.



P. & I. B. WRIGHT.

ELECTRIB FURNACE AND METHOD OF MELTING METALS AND SMELTING ORES.

' APPLICATION HiED NOV-2|. 19H.

1 ,296,896. Patented Mar. 11,1919.

4 SHEET5SHEET WITNESSES W W iNVENTORS ATTORNEY P. & I. B. WRIGHT.

ELECTRIC FURNACE AND METHOD OF MELHNG METALS KND SMELTING ORES.

APPUCATION FILED NOV. 2. I911.

1,296,896. Patented Mar. 11.19 19.

4 SHEETS-SHEET 2.

WITNESSES mvENToR:

J kfiux M 1 M- wk ATTOR NEY P. 611. B. WRIGHT.

ELECTRIC FURNACE AND METHOD OF MELTING METALS AND SMELTING ORES.

APPLICATION FILED NOV. 2|. lsu.

1,296,896. Patented Mar. 11.19191 4 SHEETS-SHEET 3.

WIZTNESSEW O mymzegi/ alga/kw a ATTORNEY P. & B. WRIGHT.

ELECTRIC FURNACE AND METHOD OF MELHNG METALS AND SMELTING ORES.

APPLICATION mzo NOV-21.1917.

- 1,296,896. Patented Mar. 11.1919.

4 SHEETS-SHEET 4.

WVITNESSES INVENTORS ATTORNEY UNITED STATES PATENT OFFICE.

PABVIN WRIGHT AND IVAN B. WRIGHT, OF SEATTLE, WASHINGTON.

ELECTRIC FURNACE AND METHOD OF MEL-TING MET4LS AND SMELTING om.

Specification of Letters Patent.

Patented Mar. 11, 1919.

Application flied November 21, 1917. Serial No. 208,154.

To all whom it may concern:

Be it known that we. Pauvrx \Vluoirr and Ivax B. Wmorrr. both citizens of the United States, residing in Seattle, in the county of King and State of 'ashington, have in vented a new and useful Electric Furnace and Method of Meltin .\Ietals and Smeltiug Ores. of which the to lowing is a specification.

This invention relates to electric furnaces as well as to methods of melting metals and smelting ores. and has for one of its objects to produce a furnace in which the material to be melted or smelted will he acted on with a maximum efficiency as regards the consumption of current.

lvith this and other objects in view the invention consists in the novel steps nd combinations of steps constituting the process and in the novel parts. and combinations of parts eon.-.titutin; the apparatus. all as will be more fully hereinafter disclosed. and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views;

Figure 1 is a diagrammatic side elevational view partly in section of a furnace made in accordance with this invention;

Fig. :2. is a view sltllllill' to Fig. l of a somewhat modified form of the invention:

Fig. 3 is a plan view of a portion of the parts shown in Fig. 2:

Fig. 4. is a view similar to Fig. 1 of another mo lifiedfor|u of furnace:

Fig. is a plan view of a portion of a still further modified form of furnace:

Fig. (3 is a sectional view partly in eleva tion of the parts shown in Fig. 5:

Fig. 'i'. is a modified diagrammatic view of circuits suitable for the constructions shown in Figs. 5 and (3: aml

Fig. 8 is a still further modified diagram of circuits suitable for the furnace shown in Fig.

The body of the electric furna e Fig. 1, is indicated at 1. it may be of any suitable construction. and is. when desirable. provided with a receptacle :2. to form a converter. or accumulating crucible. It is also provided with a relatively long vertical chute 23. forming an arc chamber into which the ore to be amelted or the. metal to be. melted. or both. are fed from a hopper -l.

Ore or scrap metal in the hopper 4, is indicated at 5 and pig iron is indicated at 6.

The pig iron 6, and the other ma etizable material is magnetically supporte and fed into the are chamber 3 by means which will now be described. The electro-magnet 7 is provided with a core suitabl suspended as by a cable 8 passin aroun a sheave 9 toa counterbalance 10, w llCh isprovided with an armature 11 adapted to be moved by a solenoid 12. Said solenoid and cable also supports the magnetic metal, or ores, suspended from said core 45. The said electromagnet 7 has its loads 13 and 14 connected to a switch 15, which in turn is connected by leads 16 and 17 to a suitable source of direct, alternating or rectified electric current supply. In the instance shown in Fig. 1, direct current is sup died to the leads 16, 17 by a. suitable reetl er 18. which receives alternatin current through leads 19 and 20 con- Ilt't'itt to a switch 21. said switch in turn being connected by loads 22 and 23 to main line conductors 24 and :25 respectively. These main line conductors are supplied with alternating current from any suitable source of su iply, not. shown.

he solenoid 12 has its leads 26 and 27 connected to a switch 28 which in turn is connected by leads '29 and 30 to the leads 17 and 16 res )ectively. Thus when the switches :21. 28 am 15 are closed the electro-magnet 'i' and solenoid 12 are energized.

Surrounding the upper portion of the arc chamber or chute 3. is an energizing or magnetizing coil 31 wound for alternating currents. and adapted to rapidly change the polarity of the magnetparticles of the combined electrode and resistor formed by the magnetizablo metals and ores suspended from core. 45 of eloetro-magne-t 7. so as to aid in preheating the. charge being fed into the furnace. This energizing coil 31 is connected by its lead 32 to a, primary coil 33 of a transformer having a core 34 and havin a secondary coil 35. The primary coil 33 is a double coil in the. instance shown. The transformer 34, having a secondary coil 35, is shown diagrammatically, and it is understood that. the same may be constructed 'in any suitable. manner to obtain maximum ellieiency as regards electrical losaes and consumption of current. 4

Another lead 36 of coil 31 is connected to a terminal 87 in the bottom of the are chamber 3, and ha a branch 38 connected to one end of a resistor 39 in the bottom of the crucible. 2. (onnected to lead 36 is a switch 40 which in turn is connected by a lead 41 to the lead 32 of coil 31.

The branch lead 38 is connected to a. switch 4'. which in turn is connected to a lead 43 that is connected to the other end of resister 3!). Thus when the switch 42 is closed the rcsister 39 is cut out, and when the switch 40 is closed the energizing coil 31 is cut out.

The said lead 43 is connected to one end of the secondar coil 35. and the other end of said coil is conncctcd to a lead H. and through the latter to a lead 51. connected at one end through a portion of the primary coil 33 to the main feeder 49 and at its other end to the core. or electrode 4:). as shown. Accordingly the secondary cur rent from the transformer will pass from the coil 3.? through the core 45 through the lnagnetizable conducting material of the charge. and aid in forming an are at the terminal 37. In other words. the. resistance in this secondary circuit through coil 31 governs the arc circuit. It follows that when the core 45 comes in contact with metal. it only closes the primary circuit. Therefore. by raising said core. or elect rode 45. we may form the arc of the melting chamber at n and there will he no such thing possible as a short circuit.

A trough 46 leads .from the tap hole 47 of the crucible 2. lhis trough. of course. may be omitted if the crucible is of the tilting type.

The line conductors 24 and 25 are connected to a switch H which in turn is connected to the leads 49. 7d) and to the primary coil It is understood that variations may he made in the electrical connections described above without departing from the spirit aml scope. of the invention as broadly defined in some of the appended claims.

In practice. the operation of the furnace in so far as it has been described is as follows: Assuming that maguetizahle ores or metals have been placed in the hopper 4 the line switch 4 will be closed to establish a circuit through the primary coil 33. lead 32, coil 31. lead 3 lI'terminal 37. metal. or ore forming the elect rode and resistcr suspended from the core 45 and through the lead 51 back to and through a portion of coil 33 to main 49, thus producing a magnetic flux in the transformer core 34. The relative number of turns in the transformer (Oils 33. 35 are such as to produce. in a manner well understood. a current of lower voltage in the secondary coil 35 than the voltage of the current flowing through the primary coil 33. The secondary current thus generated flows through the lead 44. to core 45. through the metals sus ended from said core, through terminal 3 lead 38, resistor 39 and lead 43 back to the sccondar coil 35.

Electric current a so flows from the main line conductors 24 and 25 through the leads 22 and 23, switch 21, loads 19, 20, rectifier 18, leads 16 and 17, switch 15, leads 13 and 1t and electro-magnet 7, so as to energize the latter, thus magnetizing the magnetizahle material such as pig iron, iron scrap or iron ore, as the case may be. This magnetization of the magnetizable material prevents said material from packing in the arc chamber 3 thereby reventing any decrease in the resistance to the passage of the. electric current through said material, which thus acts as a resistor. Further, the material is magnetically fed downward, so to speak, through the arc chamber 3, as it gradually melts or smelts in the lower portion of said chamber.

The flow of electricity through the resistor 39 may he continued until said resister heats the crucible hot enough to maintain it at, the melting point of the material being melted or smelted. After such melting point is reached. the switch 42 may be, closed, thus cutting out the resister 39, thereupon causiug current of comparatively heavy amperage to flow through the resistor 37 in the arc chamber.

The cnergization of the electro-ma w. causes some of the magnetite or other I: netic material in the chute 3 to ban to form a sort of combined electr e a sister. and the other portions of said triagnetite or other magnetic material to adhere to the electrode thus formed, in accordance with the well known lawsof magnetism,

with the result that the magnetic material is suspended above the molten bath indicated at 7). Thus it is clear that, as the metals at; the lower end of the magnetically nded metallic body melt, they flow into to both I and that a substantial portion of the metals iu'el in a fused state before entering said It should be noted in the foregoing described furnace that there are three distinct electrical actions conducive to the production of heat: first. the magnetic action of the energizing coil produces heat. in the adjacent portion of the body. or ore. being fed into the arc chamlier 3. such heat being incident to the rapid induced change of polarity prod-uced by the alternating current in the coil 31 second, the primary current, which is of higher voltage than the secondary current, passes through the electrode in the direction of the magnetic lines of force therein, and arcs at a. causing heat in the center of the magnetic charge; and third. the forcing of the great volume of current furnished b the secondary coil through the terminal 3 furnishes the highest degree of heat. so as to melt the ore and metal in the arc chamber 3, whence it flows into the crucible 2, where it may be treated, tap cd or ioured oil when desired. Itwill be oliserved that the overflowin of the molten metal maintains a constant. cvel in the chamber 3, and the electrode 45 does not have to be continually raised as the metal riscs in order to maintain the are. a

It is understood that either alternating or direct current may be used to energize the eleqtro-magnet 7, but it is preferable to suppl direct current to said magnet.

lVc have diagrammatically shown a lever 52 pivoted at 53 and connected to the cable 8. so that, when desired, the electro-magnet 7 may be raised manually to adjust the lower end 6 of the electrode relative to the bath b.

An overload circuit breaker 54, and an underload circuit breaker of any suitable construction may be introduced in the orefeed electro-magnet-circuit for automatic control of said ore-feed by the variation in voltage of the primary current as indicated in Fig. 1. In the instance shown these circuit breakers are inserted in the leads 13 and 14 respectively.

In the somewhat modified form of our invention shown in Fig. 2, the cable 8, sheave 9. countcr-lmlalu'e 10. armature ll, solenoid 12. primary coil 33. core 34. secondary coil 35. main line conductors 24. 25, switches 28, 48, leads 26. 27, 29. 30. 4%). 50. ore and scrap metal hopper 4 and lead 51 are, or may be the same as in Fig. 1. lint a resister 37' is substituted for the terminal 37 in Fig. 1. The body of the furnace is indicated at 57, and said furnace is provided with a vertical chute or are chamber 58 in which a nonmagnetic carbon electrode 56 is vertically (lisposed. The outlet for the molten metal such as copper ore. for example. from the are chamber is indicated at 59 and a trough I30 leads from said outlet to discln'u'gc into a crucible 61 of any suitable type. This crucible may be heated by the ame means as in the form of the invention hown in Fig. l. or not. as desired. The primary coil 33 is connected by a lead 6') to the resistor 37' and by lead 51 to the electrode 56. The secondary coil connected by leads 63. (13 to said rcsister as shown.

The lead 51 is in this modified construction connected by a lead 68 to a switch 69 which is connected to a variable resistance 70 that in turn is connected through lead 71 to lead 63.

In both Figs. 1 and 2. 72. 73 and 7-irepresent taps for coil and 75 represents a switch coacting with said taps.

in Fig. 1. cover 76 of crucible .2 is conveniently manipulated by a rope 77 passing over pulley TS. and carrying the counterpoise 79.

In the still further modified form of the invention shown in Fig- 4 the construction is similar to that shown in Fig. 1, but the lead 140 of the coil 7 is connected with the coil 31 and the lead 320 of the coil 31 is connocted with the switch 660 and through the lead 670 it is connected through coil 12 and lead 260 to the over-load circuit breaker 54 in lead 141. The lead 140 is connected by a lead 650 to switch 660 which in turn is connected through lead 670 with the lead 320, so that closing of said switch will cut out the coil 81.

The lead 430 from coil 35 connects to terminal 85, which is provided with connections 81 and 82. a

The carbon, or other refractory tube 80, is attached to terminal 85 for the purpose of conveying carbon monoxid, CO, or other reducing agents below the surface of the slag and molten ore in the crucible '2. At 82 a regulating valve 84 is attached, and to this a hose or pipe 83, connects with a supply tank. not shown, containing the reducing agent under pressure snflicient to force the gas below the surface of the slag and molten metal. The member 8? acts as a guide to keep the gas tllbc vertical in the crucible.

Some. of the features that have been described above are of course not aiplicable to the melting of non-magnetizalile metnls and smelting of non-magnetizablo ores. 'hen copper-or other non-magnetizable metals and copper ore or other non-maguctizable ores are to be treated in the fur uace, it is understood that a carbon or graphite electrode 56 will replace the iron electrode 45.

In Fig. 4 the manner of heating the cruciblc 2 is slightly different from that in Fig. 1. The secondary circuit is led from the terminal 37 by lead 38 to the terminal 39 in the bottom of the reducing crucible 2. then by means of the molten metal and slag in the crucible. contact is made with the carbon tube 80. which connects by leads 430 to coil 35. through said coil. lead 630. switch 9% and lead 97 back to terminal 3?. Throu 11 this circuit a very heavy current flows su cicnt to heat the slag and serves to maintain the ore in a molten state. The ore, which may be iron oxid, is of a high resistance when melted and mixed with only a small percentage of slag. and the iron does not separate from the mass until the reduction of the ore has taken place by the action of the (0 gas or other reducing agent forced into the metal through the refractory tube 80.

As the reduction of the ore takes place the metallic iron gravitate-s to the bottom, and below the end of tube 80. Hence. the tube 80 seldom comes in contact with the metalbut is submerged in the melted ore and slag.

Up to this point in the smelting of magnetite ore, or black sand for example no fluxes of any kind have been added. The magnetite ore readily melts and flows into chamber 2 where the reducin agent is introduced, and the reduction of iron ore, into metallic iron, readily takes place by proper manipulation which can best be attained by practice.

Switch 94 shifts the secondary circuit from lead H to lead 97; or from the are circuit through the resistor circuit. In Fig. 4 magnet 7 is shown as a horse-shoe or double pole magnet 7-7.

Coming now 'to the still further modified form of the invention shown in Figs. 5 and 6, 100 is the melting chamber discharging into the reduction chamber 200 through the duct 940. \Vhcn this chamber is filled with molten ore or metal. the flow isswitchcd into duct 950 which then fills chamber 201. The lnetal in chamber 200 is reduced or treated as may he desired and when finished is drawn off through slmllt. 460. This chamher is then allowed to fill again while the metal in chamber .201 is being treated and drawn of? through spout llil and so on. This chamber 201 it will he observed. is not a mere duplication of parts, but is necessary in order to avoid stopping the continuous operation of the melting furnace.

The stand 9120 supports the arm 380 which carries the hollow electrode 800 located in the center of chamber 200 so that by the handle 930 said electrode 800 may be raised and swung as desired. 370 represents a terminal and 390 represents a resistor identical with the parts 37 and 39 respectively as shown in Figs. 1 and 4.

Coming now to the modified diagrams of circuits shown in Figs. '7 and 8. the leads l9 and 50 are the same as in Fig. 2. as is also the converter 34. its primary 33 and secondary 35. One terminal 630 of the secondary joins the terminal 370. which is joined by the lead 380 to one end of the resister 390, the other end of which is joined by the lead fi-il to the other terminal of the, secondanv 3-"; as shown. The electrode 430 having a lower end 300 is joined to the lead 4 through a .portion of the primary by the lead 510, and is joined to the lead 50, through the are 150. terminal 370. a portion of lead 030, lead 320 and another portion of primarv The electrode 800 is likewise joined to lead 49 through a portion of the primary, a portion of lead 510, and lead 160.

It thus follows that if electrode 450 is employed like electrode 45 in a melting chamber. while electrode 800 is employed in a. crucible such as '200 or 201, then in Fig. 7 the melting chamber terminal 370 fed by the secondary 3? will be in parallel with the resistor 390 in chambers 200 and .201. while the electrodes 450 and H00 fed from the, primary 33 through lead-3:20 will be in series masses with their respective terminals and resistera 870 and 890.

In the case of Fig. 8, the terminals and 1esisters 370 and 390 are in eries with each other, and the secondary 35. The electrode 450 and terminal 370 is in series with the primary 33, while the electrode 800 and resister 890 is likewise in series with said primary through the terminal 370.

It will now be clear from the foregoing disclosure that a magnet electrode such as 45, serves as a means of feeding the iron ore or scrap down to the fusion chamber, gradually and gently, in such a manner that the furnace linings are not gouged or damaged by the sharp corners dropping or being thrown against them.

The gradual feeding is accomplished automatically if alternating current is used to excite the magnets 7 by reason of the change of polarity. Apparently the magnetic flux stops momentarll at each reversal and the magnetized material drops slightly each time until finally it. is at the bottom end 6 of the magnet and in the are.

Main line conductors 24 and 25 for electric furnace operations herein described should work under about 110 volts, single phase. If the supply should he say 2000 volts, two phase or three phase, then a two or three p iase transformer would have to be used to transform the su ply circuit down to that desired to operate tlie furnace. This would be accomplished in the usual way common 'to step down transformers and need not be shown or described here.

Vent pipe 88 Fig. 1. carries oif fumes and contains a damper 91 for regulating the draft.

Door 89 may pivot as at 90 and ham normally closed. The object of this door is to exclude the air which contains oxygen, from circulating thmugh the furnace. It will be observed that the furnace is substantially air tight.

An insulating tile (H or asbestos tube protects the coils 7 from bein damaged by heat. passing to the. upper end of the core 45.

\Vhen the. nature of the ore being smelted precludes the use of an iron electrode, then carbon or graphite is used and magnets 7 and their connections maybe dispensed with as in Fig. 2.

By the arrangement of parts described we are enabled to obtain the following results (1) Yo may effect the melting of metals and smelting of ores by a method which will intensify the are effectin the furnace.

(2) We may make rovision for magnetic feeding of magnetiznlile metals and ores to the melting or smelting chamber.

(3) \Ve may make provision, when magnetizahle metals or ores are being treated, for the fornling of an electrode from they magnetizable material while said material is being fed into the furnace and prior to the melting of said nntterial.

(4,) We. also provide for an automatic feeding of the magnetizable metal and ores to the furnace.

(5) And for an automatic electric feed of the metal and ores to the furnace.

(6) '0 make provision for the passing of both the primary and secondary currents simultaneously through the heating elements of the furnace;

(7) And make provision for the passing of both primary and secondary currents through the heating elements or resisters in series or in multiple as desired.

ll'e make )lovision for the forming of the inagnetizal ile charge. previous to its becoming molten, into an electrode.

(9) '0 cause the magnetizable charge. prior to its becoming molten. to function as a resistor.

(10) We make provision for magnetic suspension of lnagnetizable metal and ores in the furnace.

(11) c efi'ect heating of the charge by magnetization thereof.

(12) )Ve efl'ect heating of the charge by a rapid change of polarity of an alternating current.

(13) Ye eti'cct considerable heating of the charge by the use of a high voltage primary current.

(14) We preventpacking of the magnetizable material in the furnace, thereby causing greater resistance to the electric current flowing therethrongh, and thus increase the heating efi'ect of said current (15) We efl'ect automatic control of the feed of magnetizablc material in accordance with variations in the secondary circuit.

(16) \Ve may melt the ore in the furnace then flow the same into a reducing crucible, pass the secondary current. through the said crucible and metal to keep it molten and then supply CO gas or other reducing substance through a refractory tube below the surface of the metal at varying depths until the reducing action has talten place.

o claim:

1. An electric furnace comprising a chamber, magnetic means for retarding the downward movement of magnetizable material in said chamber, and means to apply heat to the material to melt it.

2. An electric furnace comprising a chamber. magnetic means for suspending magnetizable material in said chamber, and means to apply heat to the material thus suspended.

3. An electric furnace. comprisingachamber, means to suspend maguetizable material in said chamber, and means to ass an electric current through the suspem ed material.

-l. An electric furnace comprising a chamlJcl, a resistor at the bottom of the chamber,

ondary coils connected with the resister and electrode.

An electric furnace comprising achamher, a transformer having prime and secondarycoils and means to app y the primary and secondary currents from said coils to material in the chamber.

6. An electric furnace comprisinga chamber, magnetic means for suspending mag netizable material in said chamber to form an electrode, a resister in the chamber, and a transformer having its secondary coil connected with the electrode and resistor.

7. An electric furnace comprising achamber. magnetic means for suspendmg magnetizable material in said chamber to form an electrode, a resistor in the chamber, and a transformer having primary and secondary coils connected with the electrode and resistor.

8. An electric furnace comprising achamher, a resistor in the lower portion of the chamber. means to suspend a bod of metal and ores above and spaced from t e resistor, and means to supply electric current to the resistor and body of metal and ores to form an electric arc therebetween.

it. An electric furnace comprising a chamber, a re'sister in the lower portion of the chamber, means to suspend a bod of metal and ores above and spaced "from t e resister, and means to supplfy electric current to the resistor and body 0 metal and ores to form an electric arc therebctween and means of regulating the are by varying the number of turns on the primary coil.

10. An electric furnace comprising a chamber. a resister in the lower portion of the chamber, means to suspend a body of metal and ores above and spaced from the resistor, and a transformer havin its secondar coil connected with the resister and be of metal and ores to form an electric are t erebetween.

11. An electric furnace comprising a chamber, a resister in the lower portion of the chamber, means to suspend a body of metal and ores above and spaced from the rosister, and a transformer havin its primary and secondary coils connecte with the resistor and body of metal and ores to form an electric arc thercbetween.

12. An electric furnace comprising a. chamher, a resister in the lower portion of the chamber, magnetic means to suspend a body of metal and ores above and s need from the rcsister, and a. transformer avin its secondary coil connected with the reslster and body of metal and ores to form an electric arc thcrebctwecn.

l3. An electric furnace comprising a. chamber. a resistor in the. lower portion of the chamber, magnetic means to suspend a body of metal and ores above and spaced from the resistor, and a transformer having primary and seeondar' coils connected with the resister and b0 y of metal and ores to form an electric arc therebetwecn.

14. An electric furnace comprising a chamber, an electro-milgnet to suspend magnetizable material in the chamber, a resistor in the lower portion of the. chamber, and means to supply an electric currcnt to the magnet core and resistor.

15. An electric furnace comprising a chamher, an electro-magnet to suspend magnetizable material in the chamber, means adjustahly supporting the clectro-magnct, a re.- sister in the lower portion of the chamber, and means to supply an electric current; to the magnet core and resistor.

16. An electric furnace comprising a chamber, an electro-magnct to suspend magnetizable material in the chamber. a resistor in the lower portion of the chamber. and a transformer having its secondary coil connected with the resistor and magnet core to form an electric arc thcrebetn'een.

17. An electric furnace comprising a chamber, an electro-nmgm-t to suspend magnetizable material in the. chamber, a resistor in the lower portion of the chamlwr, and a transformer having primary amt secondary coils connected with the. resistor and magnet core to form an electric arc tlu-rclmtu'ccn.

18. An electric flll'nacc comprising a chamber, a rcsistcr in thc cbambcr, means to produce magnetic lines of tow-c cxtcnding longitudinally of the. chamber in the matcrial therein. and a transformer havin" its secondary coil connected with tbc rcsistcr and with said material to cause the secondary current to flow through the material parallel to the magnetic lines of force in said material.

19. An electric furnace comprisime a chamber, a resister in the chamber, means to produce magnetic lines of force extending longitudinally of the chamber in the matcrial therein, and a transformer having primary and secondary coils connected with the rcsister and with said material to causethe primary and secondary currents to lion throu h the material parallel to the magnetic ines of force in said material.

20. An electric. furnace comprising a chamber, means to suspend material in the chamber and to produce. magnetic lincs of force extending longitudinally of the chamber in the suspended material, and means to cause an electric current. to flow in said sus 'iended material parallel to the magnetic lines of force.

21. An electric furnace coml'irising a chamber. a resister in the chamber. means to suspend material in the chamber and to produce magnetic lines of force extending longitudinally of the chamber in the suspended material, and a transformerhaving its seeondarv coil connected with the resistor and with t e suspended material to cause the sexondury current to flow through the material parallel to the magnetic lines of force in said material.

22. An electric furnace comprising a chamber, a resistor in the chamber, means to suspend material in the chamber and to produce mp, tie lines of force extending longitudinefi y of the chamber in the suspended material, and a transformer havin primary seeondar coils connected wit the reslgter "and with tie suspended material to cause' the primary and secondary cur-- arallel mateto supply an alternating electric current to the coil to produce magnetic lines of force in the magnetizable charge in the chamber and means to cause a flow of electric current parallel to the magnetic lines of force.

A n electric furnace comprisin r a chumlscr, a magnetizing coil surrount ing the tlltllltlltl', a magnetic electrode passing through said coil into said chamber, means to supply an electric current to said coil to inagnet-ize material in the chamber, and means to heat said material to make it; molten.

26. An electric furnace com rising an arc chamber, a. converter chain er to receive. the overflow from the arc chamber, rcsisters in the lower portions of the respectire chamlmrs, and a transformer havin primary and secondary coils connected witi both resistors.

27. An electric furnace comprising a chamber, an clcctro-nnignet to hold material susponded in the chamber, overload and undcrload circuit-breakers connected to the olcctro-maglu-t. a source. of electric current connected to the circuit-lneakors, and means to heat the material to melt it.

28. An electric furnace comprising a chamber, an clectro-mu et to hold n'iatcrial suspended in the. cham .r. an overload circuit-breaker connected to the electro-magnot, a source. of electric current connected to the circuit-breakcr, and means to heat the material to meltit.

29. An electric furnace comprising a chamher, an electro-maguet to hold material suspended in the chamber, an underload circuit-breaker connected to the electro-magnct, a source of electric current connected to the circuit-breaker, and means to heat the material to melt it.

30. An electric furnace comprising a chamber, an electro-magnet to hold material suspended in the chamber, a solenoid, an armature movable by energization of the solenoid and connected with the electro-magnct. means to supply electric current to the electro-magnet and solenoid, and means to heat the material to melt it.

31. An electric furnace comprising a chamher, an electro-magnet to hold material suspended in the chamber. a resister in the chamber, a transformer'having its secondary coil connected to the electro-magnet core and to the resistor, and means to energize the electro-magnet.

32. An electric furnace comprising a chamber. an electro-magnet to hold material suspended in the chamber. a. resister in the, chainber, a transformer having primary and secondary coils connected to the electro-magnet core and to the resister. and means to energize the electro-magnet.

33. An electric furnace comprising a chamber adapted to receive a charge of material to be heated. a cable connected to said charge tosuspend said charge, a solenoid. an armature movable by the energization of the s0lcnoid and connected to the cable. means to energize the solenoid. and means to heat the material.

34. An electric furnace comprising a chamber adapted to receive a charge of material. a resistor in the chamber. a solenoid. means to energize the solenoid. an armature for the solenoid, an electrode inserted in the chamber. means connecting the armature to the electrode to suspend said electrode. and means to supply electric current to the resistcr and electrode to melt the charge.

35. An electric furnace comprising a chamber adapted to receive a charge of material. a resistor in the chamber. a solenoid. means to energize the solenoid. an armature for the solenoid. an electrode. inserted in the chamber, means connecting the armature to the electrode to suspend said electrode. and a transformer having a primary coil connected with the electrode and resister and having a secondary coil connected with the resister.

36. An electric fnrn ace comprising a chamber adapted to receive a charge of material. a resister in the chamber. a solenoid. means to energize the solenoid. an armature for the solenoid. an electrode inserted in the chamber. means connecting the armature to the electrode to suspend said electrode. and a transformer having primary and secondary coils connected with the electrode and reslster.

37. An electric furnace comprising a chamber adapted to receive a charge of magnetiza ble material, and means to suspend a portion of said charge and to pass an electric current therethrough while suspended to form an electrode of the suspended portion of the charge.

38. An electric furnace comprising a chamber adapted to receive a charge of inagnetizable material, and magnetic means to suepend a portion of said charge and to pass an electric current therethrongh while suspended to form a magnetized electrode of the suspended portion of the charge.

39. The method of melting metals and smelting ores, which consists in magnetizing the metallic particles of a magnetizable metal or ore, rapidly changing the polarity of the magnetized particles to produce heat in the metal or ore. and passing an electric current through the metal or ore to melt or smelt the same.

40. The method of melting metals and smelting ores. which consists in magnetically suspending the metal or ore in a chamber above a metallic body. and passing alternating currents through said suspended material to produce an electric are between the suspended metal or ore and the metallic body to make the metal adjacent the are molten.

41. The method of melting metals and smelting ores, which consists of suspending the metal or ore in a chamber above a metallic body. passing the secondary current from a transformer through the suspended metal or ore and the metallic body to produce an arc therebetween, and producing magnetic lines of force in the suspended metal or ore parallel to the flow of the secondary current in said metal or ore.

42. An electric furnace comprising a chamber, a coil above saidchamber, a core for said coil extending down into the chamber. means to energize the coil to magnetize the core. and means to cause an electric current. to flow through the core to heat magnctizable material attached to the core.

43. An electric furnace comprising a chamber, an electrode in the chamber, a resister in the chamber, a transformer having primary and secondary coils, leads connecting the primary coil to the electrode and resistor. leads connecting the secondary coil to the rcsister, and a variable resistance connecting one of the primary coil leads to one of the secondary coil leads.

44. An electric furnace comprising a chamber. an electrode in the chamber, a terminal in the chamber. a transformer having primary and secondary coils, leads connecting the primary coil to the electrode and terminal, leads connecting the secondary coil to the electrode and terminal, and a variable resistance connected across the leads of the sccpiiida'n v; coil.

45. An electric fu'iaia'ce comprising a melting chamber, an electrode and are included in the primary circuit of a transformer in said chamber. a reducing chamber adjacent thereto, a carbon tube extending into said chamber to conduct both the secondary circuit and the reducing agents into the molten metal therein.

46. In all electric furnace the combination of a chamber provided with a resistor; an electromagnetic coil above said chamber; a core for said coil extending into said chamber above said resist/er; means to energize said coil with alternating or direct currents at will; and means to pass alternating currents through said core and resister to form an arc.

47. An electric furnace comprisin an an chamber, an electro-magnet to 1101 material suspended in the chamber, a resistor in said chamber, a converter chamber to receive the overflow from the arc chamber, a carbon or other refractory tube extending into said converter chamber and means for forcing a reducing a ent through fil -id tube into the overflow mo ten material and means for keepin the material molten.

48. n an electric furnace an electrode in the primary circuit. a resister in the secondary circuit in multiple with a refractory as conveying tube, means for varying the aim of current through either circuit.

it 49. In an electric iurnare an electrode in the melting chamber. another electrode 111 the converter chamber, each connected to transformer leads and connected one with the othlerthrough the resistors at the bottom of one I. c

50. In an electric furnace the combination of a transformer provided with primary and secondary coils; a flu-mire chamber; an electrode in said chamber; a resistor in said chamber coacting with said electrode to forman are;v and connections-joining said are in series with said primary coil and mid resistor in series with said eeconda oo'iL-I 51. The method of melting material iqip electric furnace provided with arcin terminals one of which is a resistor; an r'7ith a primary coil and a secondar coilof d'transformer which consists in joining said terminals in series with said primary coil and said rcsister in series with said secondary coil, whereby the current flow in the primary coil is regulated. p i 52. In an electric furnace an clectroderifi one chamber another electrode in another chamber, one connected to energizingjedds and forlnin a circuit throughthe molten, metal and rough resisters at the bottom of ember-.1917. Ei- 1. PARVIN WRIGHT. IVAN B.- WRIGHT.

\Vmmrrr. M. M. PREH'ER.

Copies of this patent may be obtained for five cents each, by addressing the Oommlesloner of Patents.

Waahingtoml). G." n

2:65 lVashington, this 14th 2 

